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Date:   Mon, 2 Jan 2023 09:32:15 +0100
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Subject: Re: [patch] mm, slab: periodically resched in drain_freelist()
To:     David Rientjes <rientjes@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc:     Roman Gushchin <roman.gushchin@linux.dev>,
        Hyeonggon Yoo <42.hyeyoo@gmail.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
References: <b1808b92-86df-9f53-bfb2-8862a9c554e9@google.com>
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From:   Vlastimil Babka <vbabka@suse.cz>
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On 12/28/22 07:05, David Rientjes wrote:
> drain_freelist() can be called with a very large number of slabs to free,
> such as for kmem_cache_shrink(), or depending on various settings of the
> slab cache when doing periodic reaping.
> 
> If there is a potentially long list of slabs to drain, periodically
> schedule to ensure we aren't saturating the cpu for too long.
> 
> Signed-off-by: David Rientjes <rientjes@google.com>

Thanks, added to slab/for-6.2-rc3/fixes

> ---
>  mm/slab.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/mm/slab.c b/mm/slab.c
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -2211,6 +2211,8 @@ static int drain_freelist(struct kmem_cache *cache,
>  		raw_spin_unlock_irq(&n->list_lock);
>  		slab_destroy(cache, slab);
>  		nr_freed++;
> +
> +		cond_resched();
>  	}
>  out:
>  	return nr_freed;